Revolving chair



y 1945- c. s. GREENWOOD 2,377,002

REVOLVING CHAIR Filed Aug 10, 1942 INVENTOR 6502?? J marwvoa' H 6. m

ATTORNEY ".chair bases used in the "invention will hereinafter more from-:the'following :description, :considered in .con-

:neotion with the accompanying :drawing,' in

Patented May 29, 1945 UNITED STATES PATENT OFFJC E REVOLVING :CHAIR Calvin S. Greenwood, Gardner, Mass.

Application .August 10, 1942, Serial .No.ii54;286

2 Claims.

The :present invention relates .to revolving chairsgand particularly to the construction of :connection with revolving chair seats, stools and'the'like.

Theprincipahobjectof the invention is to pro vide a chair 'ofrthiszcharacter having an all wood construction, including :suitable :bearings for ro- -rtatably supporting1the standard orrshank of the chair :seat, as well :as for supporting .the weight of :the seat :itself. By .thus utilizing an :all wood construction, the employment of :metal parts,

suchas .chave heretofore been incorporated :in re- .volving chairs, is entirely eliminated, thus ren dering the chair manufacturer more or less independent'oftexistingsshortages in metals.

.A -further :object of the invention :is to provide in ran vall \wood chair construction of :the :abcve indicatedacharacter, convenient means .for adjust- :ing the :height of the seat, without the use :of

:any tools 0r.adjustable metal parts, xsuch'as have heretofore "beensemployed.

The above and other advantageous :features -.of lfully .appear which:

:Fig. dis a view-in side elevationwof a revolving chair embodying .the present invention.

Fig. :2 is a perspective View of the chair'shcwn in :Fig. '1. .60 :tilted .as {to-show :the relation :be-

tween -.the :base :construction .and the seat.

Fig. 3 is a tragmentarysectional -view on .an enlarged scale,rthrough:the chair base.

Fig. 4 is a perspective view, illustrating the arrangement of the bearing parts on the seat shank.

Fig. 5 is a sectional view similar to Fig. 3, illustratingthe improved means for adjusting the height of the chair seat.

Fig. 6 is a'horizontal sectional view along the line 8-6 of Fig. 5, looking in the direction'of the arrows.

Referring first to Figs. 1 and 2, the invention is shown as being embodied in a chair base assembly indicated by the reference character I, with the chair-base being supported above the floor level by legs 2. A .seat 3 is revolvably mounted on the base I, and provides a. suitable back 4, which can be omitted if it is desired to employ the present construction in a stool.

The under side of the seat 3 carries a shank plate 5, and as best shown in- Fig. 3, this plate provides a centrally located opening 6, within which is received the upper end of a shank 1 extending downwardly through the base I. The

-B driven into a slot -9 to the under for the base,

plate l4 rigidly secured to tionszl I, which radiate from the hub structure.

'lar seat l8 lying ina are secured to a solid cylindrical hub member 12 providing :a central passage 13, through "which the shank 7 'freelyextends. hub member l2 form aself supporting assembly and the present invention is :particularly concerned with :the provision of means for rotatably supporting both the shank 1 and theseat 3 on the base structure, withoutthe use of anymetal bearing.

To this end, the base provides a top bearing the assembled legipor- The plate 14 provides .an opening 15 of greater diameter than the shank 1, and this opening is provided with an.enlarged seat l5 for receiving .a sleeve bearing 47, the internal :diameter of which is such as :to provide a running 'fit with the shank "l. The sleeve bearing i! "is formed of wood impregnated with a :suitable lubricant.

The uppersurface 0f the plate I4 is countersunk around the seat It .to :provide a wideannuhorizontal plane, and .concentric with the seat I 6, which receives the sleeve bearing l1. bearing disk IQ of annular form which, as best shown in Fig. 4, provides acentral opening 20 loosely surrounding the shank 1.

It will be noted frOm Fig. 3 that the thickness of the bearing disk I9 is somewhat greater than the vertical depth of the seat l8, so that the upper surface of the disk I 9 directly supports the lower surface of the shank plate 5. That is to say, when the shank I has been inserted in the hub and centered therein by the sleeve bearing H, the weight of the seat 3 is largely borne by the relatively large area of the bearing disk t9. The disk I9 is composed of wood impregnated with a lubricant, such as oil or graphite, so that the seat will always turn freely on the base. In fact, it has been found that after the chair has been in use, the lubricant with which the disk I9 is impregnated works into the fibres of the lower face of the shank plate 5, to such an extent that the seat 3 turns with great freedom.

Thus, the legs 2 and This seat l8 freely receives a flat The lower end of the hub structure is provided I hub structure. The plate 2! is formed with an opening. 22 of slightly greater diameter than the shank 1, above which opening 22 the hub member I2 is provided with an enlarged seat 23 for receiving a cylindrical bearing sleeve 24 held in position by the plate 21. The inside surface of this bearing sleeve 2 makes a running fit with the shank, and the sleeve 2% is also composed of wood impregnated with a lubricant.

From the foregoing, it is apparent that the wooden shank l carried by the plate 5 is sup-- ported for turning about a vertical axis, in such manner that side play is prevented. Due to the lubricant which impregnates the sleeve bearings H and 24, the fibres of the shank l absorb this lubricant after the chair has been in use, so that the shank will tu n freely, and can be readily withdrawn from the base. Wear between the shank l and the sleeve bearings ll and 2d is reduced to a minimum, due to the fact thatthe weight of the seat and its occupant is born by the bearing disk it which, as previously pointed out, provides a bearing surface of considerable area, as compared to the cross sectional area of the shank l.

As previously pointed out, the invention also contemplates an all wood chair base construction, which will permit the chair seat 3 to be adjusted for different heights, without disturbing the arrangement and functioning of the varying elements previously described. Such a modified construction is shown in Fig. 5, wherein parts having the same functions as in Fig. l are designated by the same reference characters.

In the modified structure, the sleeve bearing H and the flat bearing disk it are carried by an intermediate bearing plat 25, from the lower surface of which extends a set of diametrically opposed spacing pins 28 extending downwardly in the direction of a top plate 23 forming part of the hub structure. As best shown in Fig. 6, the hub plate .2? is provided with a series of" openings 28, 29 and 3d of different depths, such openings being arranged concentrically about the axis of the shank l at the same radial distance therefrom as the pins 26. It will be noted that the top surface of the plate ll provides equal spaces between the members of each series of openings, and that the openings 28, 29 and 3d of the same depth are diametrically opposed with respect to the shank axis. Therefore, all four pins 26 may be received in any given series of openings 28, 29 or 30, or may rest on the top of the plate 21 between these openings.

With the above described arrangement of spacing pins 26 and openings 28, 29 and 36, it is possible to adjust the distance between opposed faces of the plates 25 and 21, and so determine the height of the seat 3 above the floor. For example, with the pins 26 received in the openings 39, which extend through the plate 21, the plate 25 is resting on the plate 27, and the seat 3 is at its lowest level. However; with the pins 26 received in the openings 29 of intermediate depth, as shown in Fig. 5, the seat 3 will be supported at a level intermediate between the levels obtained, with the pins received in the openings 28 and 39, respectively.

I claim:

1. A revolving chair construction comprising in combination a seat provided with a downwardly extending shank, a base provided with a central opening for receiving said shank and of greater diameter than said shank, a top plate mounted on said base provided with a central opening for receiving a sleeve bearing fitting a portion of said shank where it enters said base opening, with said top plate having its upper face provided with a countersunk recess surrounding said sleeve bearing, and an annular bearing disc received in said recess for supporting said seat, with said shank being composed of wood and said sleeve bearing and disc being composed of wood impregnated with a lubricant.

2. A revolving chair construction comprising in combination a seat provided with a downwardly extending shank, a base provided with an open ing for receiving said shank and of greater diameter than said shank, with the upper portion of said base provided with a plurality of series of openings of different depths arranged in spaced relation around the shank axis, a plate provided with an opening in which is received a sleeve bearing surrounding a portion of said shank, with the central portion of the upper face of said plate being countersunk to receive an annular bearing disc for supporting said seat, and with the lower face of said plate provided with a series of downwardly projecting pins spaced around the shank axis for reception in different series of said openings to support said bearing plate and seat at different levels with respect to said base.

CALVIN S. GREENWOOD. 

